King Jim Digital Ear Muffs MM1000 White #KingJim ● Cuts out noise while allowing voices to be heard. ● A small microphone built into the earphones picks up ambient noise and cancels it out by emitting sound waves of the opposite phase. ● For studying ● For commuting on public transportation ● Cord: Yes (850mm) ● Size: Free ● NRR value (dB): 20 ● Noise cancellation level: Up to -20dB ● Power supply: 1 AAA alkaline battery (sold separately) ● Battery life: Approximately 100 hours with alkaline batteries (varies depending on usage conditions) ● Earplug body: ABS resin ● Pouch ● Earpieces (XS, S, M, L) ● Examples of sounds for which the effect cannot be expected: Extremely loud noises such as those in a factory, high-pitched sounds such as metal clanging, the sound of breaking glass, snoring, teeth grinding, sneezing, coughing, dog barking, etc. I tried them after purchasing, but they didn't fit, so they've been stored on a shelf. The earpieces other than the size that was attached are unused. There is no packaging. The items in the images are all that are included. These are items stored at home, so please understand before purchasing. The batteries will be removed before shipping. Please prepare your own. I apologize if I have overlooked anything. I have pets. Please check my profile. I would be happy to pass these on to someone who needs them. Thank you very much.